Positive and automatic warp let-off apparatus for power looms



AJune 2, 1959 FusAKlcHl KoNDo 2,388,955

PosTTTvE AND AUTOMATIC wARP LET-OFF APPARATUS Fon POWER Looms Filed Aug.28, 195e United States Patent F PGSITIVE AND AUTOMATIC WARP LET-OFFAPPARATUS FOR PWER LOOMS Fusakichi Kondo, Tado-machi, Kuwana-gun,Mie-ken, Japan Application August 28, 1956, Serial No. 606,642

8 Claims. (Cl. 139--99) This invention relates generally to power loomsand more particularly to a positive and automatic warp letoff apparatusfor power looms.

The apparatus according to the invention is characterized in that it hasa plurality of freely mounted warp letoif rolls between the warp beamand the back rest roll; and in that it has two groups of ratchetmechanisms arranged side by side in front of the frame and driven byoscillatory motion of the lay sword. One group of ratchet mechanismsdrives the said warp let-off rolls the other group drives the clothdriving roll to keep up constant driving speeds of the warps and thecloth with an optional speed ratio. The apparatus is furthercharacterized in that it has changing and separating mechanism for thesaid ratchet mechanism to enable, if necessary, reversing or idlingmotion without changing the tension of the warps; and in that the warpsare guided successively in counter directions to the said warp let-offrolls the two ends of which are operatively connected to the said warpbeam and the back rest roller in the directions that the warp let-off`rolls may be pressed toward each other by the warp tension so that thewarps are let oi by the let-oif rolls with automatic changeable pressurebetween them which is proportional to the warp tension.

The principal object of the present invention is to provide a practical,simple and easily operated apparatus which can weave uniform cloth andreduce breaking of warps let off from the warp beam by positive andautomatic warp let-off and cloth take up, Iwhich takes placeintermittently from the oscillatory motion of the lay sword, having aregulated constant peripheral speed ratio.

Up to the present time, two types of equipments have been used forlet-off warps in looms. The one type uses a passive method which has abrake on the warp-beam and supplies warps by pulling them against thebraking force, the other type makes use of a positive method whichsupplies warps by rotating the warp beam positively by a mechanism whichresponds to the tension of warps. In both methods, however, the warpsupplying motion is caused by the tension of warps themselves which areto be let olf. In the first mentioned type the warp beam is rotateddirectly by the warp tension and in the second mentioned type themachine is constructed so as to adjust the mechanism which positivelydrives the Warp beam by a movable back rest which responds to thetension of warps. As a result, a strong tension is constantly applied onthe warps, especially the tension on warps which can withstand the leasttensile strain, for example cotton threads in woolen yarn, becomes sogreat that it causes non-uniformity of Warp winding on the beam andfinally break.

And, moreover, because of the time lag between the change of warptension and let-oli or take-oil motion of warps, the warp let-off is notuniform and it causes stripes in the woven goods.

This can result in low work speeds or rate, expense ,for alteration ofproducts and the necessity of extra raw Patented June 2, 1959 materials.In order to avoid these shortcomings, ac. curate machine adjustment yanda high degree of operator skill in weaving are necessary and in spite ofthese careful attentions, satisfactory results cannot be expected.

In the present invention, however, these difficulties are avoidedbecause the take-off or let-off mechanism of the warps is correlatedwith the cloth take-up mechanism and they are both driven positively inorder to give a certain speed ratio of cloth winding to warp supply; asa result a constant tension is applied to the warps, warp supply isuniform, and breaking of warps and aws in the cloth are avoided.

We can think of another method for rotating the warp beam by the powershaft to supply warps mechanically and positively but in this method,keeping constant the rotating speed of the warp beam, warps tend to bestrained as the outside diameter of the warp beam decreases. Because ofthis tendency it is necessary to gradually decrease the cloth take-upmechanism speed, for instance, and other corresponding considerations.But it is very diiiicult to accomplish all this.

In this invention, not the warp beam but a plurality of freelyoperatively combined let-off rolls between the warp beam and the backrest roller are mechanically driven, so when the rotating speed of thelet-oi rolls is constant, the warp let-off speed is kept constantindependently of the outside diameter of the warp beam Winding and whenthe cloth takeup mechanism speed is kept constant, by making constantthe rotating speed of the cloth driving roller, the change of warptension due to the change of spool diameter is completely excluded.

In addition, the warp let-off rolls are driven by worms and arecooperatively, operationally combined freely with each other so they arepressed toward. each other with pressure proportional to the warptension, and as the result it is very easy to install and exchange thewarp and to meet any sudden change of the warp tension, i.e. the shockdue to oscillation, to avoid the slip of warps and the stripes of wovengoods.

As the warp beam is freely supported the application of a little warptension is able to `drive the warp beam and, even in the case of mixweaving, non-uniformity of the warp spool and the Warp breaking areavoided. Experience with the invention indicates that rolls having arelatively high coefficient of friction are most suitable for the warplet-oif rolls for wool looms.

ln the present invention, the Warp let-oil? rolls and the cloth drivingroll are separately driven by two groups of ratchet mechanism which aredriven by the oscillating motion of the lay sword. Each group isarranged side by side in front of the loom frame and is separated forthe warp and for the cloth and driven through their own rivingmechanism, so the operator can easily control the driving condition ofthe two groups and the forward, stoppin-g or backward motion of either.The warp let-V oif and the cloth take-up can be easily and` separatelyperformed. As the two groups of ratchet mechanism each have two ratchetwheels, forward and backward, and engaging claw members, they can bearranged to operate forward, backward or stop at one time and by oneoperaion.

Since shrinkage between the warps and the woven cloth is almost within afixed limit, for Woolen fabrics about i2% around 5%, when the peripheralspeeds of the warp let-off rolls and the cloth `driving roll aredetermined corresponding to the mean value of shrinkage, the same numberof cogs for both ratchet wheels are used for the mean shrinkage valueand different number of cogs are used selectively in other cases and sohalf number of ratchet wheels is sufficient for responding to a. rangeof various speeds.

assente- Asa result of the arrangement mentioned above, there is adecrease of warp breaking decreasing downtime of the loom. Experimentsshow the working rate Yincreases from70% Yto more than 90% fo'r woolenfabrics; stripes in woven cloth are eliminated making the cloth uniform,the weight of the product-s is standardized, excess use of raw materialis avoided, operational limits of looms are extended because problemscaused both by hardness and thickness of materials and products areeliminated. Moreover, adjustment and control of the machine is so easythat unskilled workers can produce high class cloth quite easily.

A preferred embodiment of this invention is illustrated by way ofexample in the accompanying drawings, in which:

Fig. 1 is a partly sectional side elevation view of a warp let-olfapparatus according to the present invention,

Fig. 2 is a fragmentary front view of a portion of the apparatus shownin Fig. 1,

Fig. 3 is a fragmentary perspective View showing a ratchet mechanism ofthe apparatus of Fig. 1.

Referring `to the drawings 1 is a warp beam and warps 2 spooled on 1 areled through four warp let-off rolls 3 to a back rest roll 4, thenthrough a heald 5 and a reed 7 attached to an upper part of a lay sword6. The warps are Woven into a cloth 8, and are guided by a breast beam 9and a cloth driving roll 10. The woven cloth is taken up by a clothtake-up roll 11. The lowermost letoff roll 3 is pivotally mounted on afixed axis and the other rolls 3 are pivotally mounted on a memberhaving a slot 3b schematically shown in Fig. l so that their axes maymove toward the axis of the lowermost roll 3. The four warp let-olfrolls 3 are each freely operatively combined or caused to cooperate asherein later described, and the warps 2 are guided interlaced onopposite sides of the rolls 3 in sequence, and both ends of the warps 2are operatively associated with the warp beam 1 and the back rest 4 independence upon the directions that the warp let-of`f rolls are pressedmutually by the tension of the warps 2. A crank shaft 12, through aconnecting rod 13 causes oscillatory movement of the lay sword 6 on apivot shaft 14. A connecting piece 16 is `carried on `an end of a lever1S which is fixed on the l-ay sword 6 connecting, to the lay sword, apart of an L-shaped piece 1S which is pivoted on a shaft 17.

On a rotating shaft 19 is freely supported a piece 20, which has twoelongated guide slots a and b on it, and a guide pin 21 is inserted andfixed through a guide slot c on the L-shaped piece 18 and the guide slotb above mentioned. On the rotating shaft 19 are fixed ratchet wheels orcogwheels 22 and 23 one above the other which have opposite peripheralcogs `as shown. A handle or wheel 24 is disposed adjacent to thecogwheels on shaft 19. Claw members 26 and 27 are joined by a pin 2S inthe guide slot a as to operatively engage with the cogs of the ratchetwheels 22 and 23. The other end of the rotating shaft 19 is connected toanother rotating shaft 31 through a universal joint 28, a connecting rod29 and a universal joint 30;

On the rotating shaft 31 is xed a bevel gear 32, with which is engaged abevel gear 33. A driving shaft 34 is fixed to the bevel `gear 33 andsupports two worms 35 on it, the lower one of which is xed and the upperslidably keyed, and they are engaged to two worm wheels 36 which arefixed on the two alternately arranged warp let-off :rolls 3. A lever 38is provided with a pin 40 disposed in a guide slot of the framemaintaining contact with both a roller 37 attached to the lay sword 6and the back rest roller 4. An adjusting piece 41 is attached to thelever 38. On the other end of the reed 7 used for driving filling isfixed another lay sword 6', corresponding to the lay sword 6 abovementioned, which is connected to the crank shaft 12 through a connectingrod 13' and is pivotally joined to the shaft 14. From the lay sword 6',corresponding to the elements associated Awith lay sword 6 are disposeda lever 15', a connecting piece 16', an L-shaped piec 1S', a pin 21', apiece 20', claw members 26' and 27', ratchet wheels 22 and 23', arotating shaft 19' and a handle 24' which are attached to the other sideof the frame. A wonm 42 fixed on the rotating shaft 19 is engaged to aworm wheel 43 which is fixed to the cloth driving roll 10.

The action of the apparatus is as follows:

When the crank shaft 12 turns, the lay swords 6 and 6' are oscillated onthe shaft 14 by the connecting rods 13 and 13' and the reed 7 on theupper part of 6 and 6' makes one driving operation for each rotation ofthe i crank shaft 12. At the same time, the roll 37 on the lay sword 6pushes the lever 38 which in turn makes an oscillating motion around theshaft 40 and controls the warp tension by shifting the back rest roll 4in connection with the motion of the heald 5 which is driven by othermechanism (not shown).

The levers 15 and 15', the connecting pieces 16 and 16', the L-shapedpieces 18 and 18' and the pieces 20 and 20' move in the direction shownby arrows due to the oscillating motion of the lay swords 6 and 6'. Foreach movement, the claw members 26 and 26' drive the ratchet wheels 22and 22', and which also drive the rotating shafts 19 and 19'intermittently. The shaft 19, in turn, drives the driving shaft 34intermittently through the connecting rod 29, the rotating shaft 31, thebevel gears 32 land 33 'and it also drives the warp let-off-rolls 3through the worms 35 and worm wheels 36. By these motions, the warps 2are supplied intermittently from the four adjacent warp let-olf rolls 3.On the other hand, the rotating shaft 19' drives the cloth driving roll10 through the worm 42 and the worm wheel 43, and the woven cloth 8 istaken up intermittently to the cloth take-up roll 11 with a constantrunning speed which is determined by the let-olf speed of the warps 2having no connection with the outside diameter of the cloth taken up onthe roll 11, through the ratchet mechanism which is related to the laysword 6 and a friction disc mechanism (not shown).

It is possible to change the ratio of the warp supplying speed to thecloth take-up speed corresponding to various kinds of cloth material byusing different ratchetV wheels 22 and 22. When it is necessary to missthe beating for some reason, the claw members 26, 27 and 26', 27' can bedisconnected with the ratchet wheels 22, 23 and 22', 23' by a connectingmechanism fixed to 26, 27 and 26', 27 (not shown) and the shaft 19 and19' stop. Therefore, the supply of the warps 2 and takeup of the cloth 8are also stopped leaving only the weft supplying and beating in motion.

The machine can be reversed by engaging the claw members 27 and 27' withthe reversely turning ratchet wheels 23 and 23'. In this case, the warplet-off rolls 3, the cloth driving roll 10 and the cloth take-up roll 11are driven in the reverse direction but the warp beam 1 is driven Vinthe same direction, and so the direction of movements of the warps 2 andthe cloth 8 is reversed, the warps 2 are relaxed between the warplet-oil: rolls 3 and the warp beam 1 but no relaxation takes placebetween the warp let-off rolls 3 and the back rest roller 4, and asimple reverse can be done without loosening the cloth take-up roll 11and turning the warp beam 1 by hand. Because the connection anddisconnection of the claw members 26, 2'7 and 26', 27 to the ratchetwheels 22, 23 and 22', 23' can be made together as Well as separatelythrough or without the connecting mechanism, the warps 2 or the cloth 8can be supplied or taken up by controlling the wheels 24 or 24'disconnecting one of the connecting mechanism concerned.

I do not desire to limit myself to the particular construction andarrangement of the parts herein shown and described, since it is obviousthat many changes can be made without departing from the spirit andscope of my invention as defined in the appended claims.

What I claim is:

1. In a loom having oscillatably driven lay swords and warp left-oit andcloth take-up mechanisms, the take-up mechanism comprising a drivencloth take-up roll, a plurality of removable and interchangeableintermittently driven ratchet wheels, a cloth delivery roll drivenintermittently by said ratchet wheels for delivering linished cloth tothe take-up roll, means cooperating with said lay swords for drivingsaid ratchet wheels at least in one direction at selected speeds Withina predetermined range of speeds, said let-off mechanism comprising aplurality of cooperating let-olf rolls, a warp beam, means driven bysaid ratchet wheels for driving at least one of said let-off rolls atselected speeds within a predetermined range of speeds thereby to let-oiwarp from the beam in selected speed ratios relative the speed of thecloth delivery roll.

2. In a loom having oscillatably driven lay swords and warp let-off andcloth take-up mechanisms, the take-up mechanism comprising a take-uproll driven at substantially a uniform speed, a plurality of removableand interchangeable intermittently driven ratchet wheels, a clothdelivery roll driven intermittently by said ratchet Wheels fordelivering finished cloth to the take-up roll, means cooperating withsaid lay swords for driving said ratchet wheels at least in onedirection at selected speeds Within a predetermined range of speeds,said let-ott mechanism comprising a plurality of cooperating let-cfr"rolls, a Warp beam, means driven by said ratchet Wheels for driving atleast one of said let-ott rolls at selected speeds within apredetermined range of speeds thereby to let-oil warp from the beam inselected speed ratios relative the speed of the cloth delivery roll.

3. In a loom having oscillatably driven lay swords and warp let-ott andcloth take-up mechanisms according to claim 2, in which some of saidratchet Wheels drive said cloth delivery roll and other ratchet Wheelsdrive said let-olf rolls, said wheels driving the let-olf rolls beingadapted to drive the rolls with a peripheral speed 5 percent greaterthan the peripheral speed of the cloth delivery roll.

4. In a loom having oscillatably driven lay swords and warp let-ott andcloth take-up mechanisms according to claim 2, in which said ratchetwheels comprises two pairs of wheels, each pair having the wheelsarranged for opposite rotation, one of said pairs cooperating fordriving said cloth delivery roll in two directions and the second paircooperating for driving the let-olf rolls in two directions, said pairsof ratchet wheels being replaceable with other wheels having a selectednumber of teeth determined as a function of the shrinkage factor of thewarp material.

5. In a loom having oscillatably driven lay swords and warp let-off andcloth take-up mechanisms, the take-up mechanism comprising a drivencloth take-up roll, a plurality of removable and interchangeableintermittently driven ratchet wheels, a cloth delivery roll drivenintermittently by said ratchet wheels for delivering finished cloth tothe take-up roll, means cooperating with said lay swords for drivingsaid ratchet wheels at least in one direction at selected speeds Withina predetermined range of speeds, said let-oir mechanism comprising aplurality of cooperating let-oft rolls, a warp beam, means driven bysaid ratchet wheels for driving at least one of said let-0E rolls atselected speeds within a predetermined range of speeds thereby tolet-olf warp from the beam in selected speed ratios relative the speedof the cloth delivery roll, and a tensioning roll cooperating with saidlet-oi rolls and said lay swords for maintaining a preselectedsubstantially constant tension on the warp during all operations of theloom.

6. In a loom having oscillatably driven lay swords and warp let-off andcloth take-up mechanisms, the take-up mechanism comprising a drivencloth take-up roll, a plurality of removable and interchangeableintermittently driven ratchet wheels, a cloth delivery roll drivenintermittently by said ratchet wheels for delivering nished cloth to thetake-up roll, means cooperating with said lay swords for driving saidratchet wheels at least in one direction at selected speeds within apredetermined range of speeds, said let-off mechanism comprising aplurality of cooperating let-olf rolls, a warp beam, means driven bysaid ratchet wheels for driving at least one of said let-oli rolls atselected speeds within a predetermined range of speeds thereby tolet-oit warp from the beam in selected speed ratios relative the speedof the cloth delivery roll, means for selectively rendering saiddelivery roll and said let-oir rolls inoperative thereby to precludedriving by said wheels, and means for selectively operating the let-olfrolls and cloth delivery roll manually.

7. In a loom having oscillatably driven lay swords and Warp let-off andcloth take-up mechanisms, the take-up mechanisms, the take-up mechanismcomprising a driven cloth take-up roll, a plurality of removable andinterchangeable intermittently driven ratchet wheels, a cloth deliveryroll driven intermittently by said ratchet wheels for deliveringfinished cloth to thel take-up roll, means cooperating with said layswords for driving said ratchet wheels at least in one direction atselected speeds within a predetermined range of speeds, said let-olimechanism comprising a plurality of cooperating let-olf rolls includinga pair of driven let-olf rolls, a warp beam, means driven lby saidratchet Wheels for driving said pair of letoi rolls thereby to let-ottwarp from the beam in selected speed ratios relative the speed of thecloth delivery roll, and a pair of friction rolls disposed alternatelywith said let-oir rolls and cooperating therewith.

8. In a loom having oscillatably driven lay swords and warp let-oi andcloth take-up mechanisms according to claim 7, in which said pairs oflet-oit rolls have their longitudinal axes disposed radially of eachother and substantially in the same plane, including means pivotallymounting one of said driven let-olf rolls in a lixed position, means formounting the other rolls radially above of said last mentioned roll withtheir axes freely movable radially of one another, the warp beingdisposed over the uppermost let-oir roll between the rolls andalternately on opposite sides of alternate rolls, and means comprising awarp tensioning roll cooperating with said let-01T rolls for maintaininga constant tension on the warp.

References Cited in the le of this patent UNITED STATES PATENTS1,737,600 Lucas Dec. 3, 1929 2,303,297 Budzyna et al. Nov. 24, 1942FOREIGN PATENTS 386,791 Germany Jan. 27, 1922

